1. Field of the Invention
The present invention relates generally to motor control devices, driving devices, conveyor devices, image forming apparatuses, motor control methods, and computer-readable recording media.
2. Description of the Related Art
It is known that certain types of conventional image forming apparatuses are equipped with a plurality of motors including a motor for conveying paper for use in image forming. Known techniques for controlling such a motor include the following. That is, a CPU (Central Processing Unit) transmits a control signal, such as a PWM (Pulse Width Modulation) signal, corresponding to a control voltage to be applied to the motor to a motor driver. The motor driver drives the motor in accordance with the control signal.
However, such an image forming apparatus is disadvantageous in that, if a motor is started to rotate in reverse direction when the motor is rotating (including when the motor is decelerating), because a counterelectromotive force and a voltage applied to drive the motor are in the same direction, a high voltage is undesirably applied to an armature, which can result in breakdown of the motor.
To avoid this disadvantage, a motor control device that prevents a motor that is rotating from being started to rotate in reverse direction is disclosed in, for example, Japanese Patent No. 3962556. The motor control device of Japanese Patent No. 3962556 is configured to, even when a rotor of a permanent-magnet brushless direct-current motor is rotating in a reverse direction opposite to a designated rotation direction, reverse the rotation direction of the motor, thereby rotating the motor in the designated rotation direction.
However, the motor control device of Japanese Patent No. 3962556 is disadvantageous in that it is necessary to detect the rotation direction of the motor to determine whether or not to start up the motor.
Therefore, there is a need to provide a motor control device, a driving device, a conveyor device, an image forming apparatus, a motor control method, and a computer-readable recording medium capable of controlling rotation reversing of a rotating motor without detecting a rotation direction of the motor.